Author: eduardofv

I’ve found that my copy of the book Cosmos by Carl Sagan, ISBN 9780345539434 (2013 Ballantine Books Trade Paperback Edition) is missing several square root symbols on Appendix 1, pages 370 and 371 which make following the proof a bit confusing. See images below. Hope this helps.

Eduardo Flores

9/14/2017

Question: When transforming vectors to their Principal Components, are their relations preserved?

We have a set of vectors. After performing Principal Component Analysis (PCA) we now use the “rotated” vectors to perform analysis. Can we be confident that the original relations (cosine similarity between vectors) are preserved on the new vector space?